Don’t leave a trace: Private Browsing in Firefox

Today, a major feature was added to the pre-release versions of Firefox 3.1, called Private Browsing.  I’ve been working for quite some time on this, so I thought it may be a good time to write about what this feature is and how to use it.

As you may know, while you browse the web, your browser usually records a lot of data which will later be used to improve your browsing experience.  For example, it records a history of all the web pages you have visited, so that later if you need help remembering a site you visited a while back, it can assist you in finding that site.  Now, that is great, but there is a downside: those data can be used to trace your online activities.  For example, if your coworker sits at your computer, she can view all of your browsing history, which may not be what you want.

Suppose you’re doing something online, and you don’t want your coworkers know about it.  An example scenario would be looking for a new employer while at work!  One option would be to do your work, and then clear the data that Firefox has stored for you, such as history, cookies, cache, ….  But the problem is that this action will also remove the parts of your online activities data which you don’t want to hide, so the history that Firefox records can no longer be used to find a web site you had visited a month before.  Private Browsing will help you here.

Private Browsing aims to help you make sure that your web browsing activities don’t leave any trace on your own computer.  It is very important to note that Private Browsing is not a tool to keep you anonymous from websites or your ISP, or for example protect you from all kinds of spyware applications which use sophisticated techniques to intercept your online traffic.  Private Browsing is only about making sure that Firefox doesn’t store any data which can be used to trace your online activities, no more, no less.

So how does one actually use this feature?  It couldn’t be simpler!  To start, just select Private Browsing from the Tools menu.

To start, just select Private Browsing from the Tools menu.

You will see a dialog box which asks you whether you want to save and close all of your current windows and tabs, and start the Private Browsing mode.  Click Start Private Browsing to start your private session.

Click Start Private Browsing to start your private session.

After you do this, your non-private browsing session is closed and a new private session is opened, showing you the screen below.  (Before you mention, the ugly icon you see there is something I created as a placeholder!  This icon will be replaced in the final release of Firefox 3.1.)

Start of the Private Browsing mode

As you see, not much is different in the Firefox window inside the Private Browsing mode, except for the (Private Browsing) text added to the title bar at the top of the window.  That is intentional: after all, if you’re doing something online that you don’t want your coworkers to know about, you don’t want to raise their attention with a big sign saying PRIVATE as they pass by and glance over your shoulder. 

At this stage, you can start browsing web sites, without ever having to worry that Firefox might store something on your computer which can be used to tell which pages you have visited.  Once you’re done, just uncheck the same menu item in the Tools menu to close your private session.

Once you're done, just uncheck the same menu item in the Tools menu to close your private session.

 This action discards all of the data from your private session, and will restore your non-private browsing session, just like it was before entering the Private Browsing mode.

This action will restore your non-private browsing session, just like it was before entering the Private Browsing mode.

Now, as I mentioned at the top of this post, this feature is available in pre-release versions of Firefox 3.1 (what we geeks call nightly builds).  This feature will be included in Firefox 3.1 Beta 2 which will be released soon, so if you want to try it, you can give it a shot then.  And of course, it will appear in the final release of Firefox 3.1, so if you’re not the type who test beta software, you can wait until Firefox 3.1 is released.

Update:  As many people seem interested in knowing this, there is a way to make Firefox always start in Private Browsing mode.  Go to the about:config page, click I’ll be careful, I promise, type browser.privatebrowsing.autostart in the Filter text box, double click the entry to make its value true.  After doing this, the next time you start Firefox, it will start in private browsing mode automatically.  To turn this off, use the same steps to change the value of this preference to false.  There is a plan to provide an easier method to set this option in the final release of Firefox 3.1.

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319 comments on “Don’t leave a trace: Private Browsing in Firefox
  1. Michael says:

    Nice to see yet another write up of private browsing that doesn’t mention it’s usefulness at hiding browsing of porn! I imagine this feature will get a lot of coverage – I wonder if any of it will actually mention porn. (Of course I realise that there are other real uses for the feature, and porn isn’t something that everyone wants to discuss or be associated with – and that of course is why this privacy feature is useful for it…)

    Anyway, good work on getting it done – it’s obviously not easy implementing a feature which touches so many parts of the code.

  2. Aaron Train says:

    Congrats Ehsan!

    All the hard work paid off, good to see the work done!

    - Aaron T

  3. Dave says:

    “Suppose you’re doing something online, and you don’t want your coworkers know about it. An example scenario would be looking for a new employer while at work! ”

    Every company with more than a few hundred employees will probably have some sort of internet monitoring installed. So you aren’t defeating anyone by entering private mode.

  4. crf says:

    What about flash cookies? Does it handle them as well?

  5. Wayne Alligood says:

    Very good work. This is certainly something I’ve been waiting for. Keep up the good work.

  6. Ehsan Akhgari says:

    Thanks!  Yes, porn might be a very compelling example here.  Mozilla already includes such features, such as libpr0n

  7. Ehsan Akhgari says:

    Thank you for helping out in writing some unit tests for the feature — great job!

  8. Ehsan Akhgari says:

    Yes.  But like I mentioned in the post, Private Browsing only ensures that Firefox doesn’t store any data which can tie your browsing activities to a specific site.  So, as long as the only employees you want to protect from are the ones who sit at your computer and browse through your history and stuff, you should be fine with Private Browsing mode.

  9. Ehsan Akhgari says:

    No, we don’t currently handle them, and I don’t expect this to ever happen in Mozilla core.  But this is also something which extension authors might look into as well.

  10. Ehsan Akhgari says:

    Glad to hear it.  Your feedback is highly appreciated, so please don’t hesitate to let me know if you have any suggestions/criticisms.

  11. skierpage says:

    Thanks for the feature, I just tried it in Firefox 3.1 nightly and it worked fine. Here’s another way to get similar private browing that I think works in Firefox 2 and 3.

    I have a profile in Firefox named “testing” with Tools > Options > Privacy > “Always clear my private data when I close Firefox” checked and set to throw away everything.

    If I start Firefox with the command-line options “-no-remote -P” , I can run a second instance of Firefox along with my regular instance; it prompts for a profile. That second instance doesn’t save anything.

    I use this to reproduce Firefox bugs in a bare-bones profile with no add-ons or history while entering bug reports in my regular profile; but it’s also useful for private browsing and I can keep my 12 regular tabs and multiple windows going.

  12. Ehsan Akhgari says:

    Thanks for sharing this solution.  Please note though that this is not really equivalent to what Private Browsing provides.  Private Browsing ensures no such data ever gets written to disk, so for example if your browser crashes along the way, nothing will be left on disk.  Also, with Private Browsing, what you get is really a version of Firefox with all of your customizations (extensions, themes, settings, bookmarks, etc.), not a brand new profile which you need to customize from scratch to match your specific taste.

  13. skierpage says:

    I have Tools > Options > Privacy > Cookies set to “Ask every time”, and when I first visit a site and get the “Confirm setting cookie” dialog I either allow session cookies or deny cookies (and, rarely, allow permanent cookies) and remember the decision for each site. It’s a hassle but lets me blacklist some sites and deny permanent cookies to most.

    When I switch to private browsing, sites still ask me if I can set the cookie, but I can’t check “Use my choice for all cookies from this site” because the checkbox is disabled So I keep getting the “Confirm setting cookie” dialog over and over.

    I assume the handling of cookies in Private Browsing is “Allow for session”. I would document that this is the setting in Private Browsing, that it can’t be changed, and that “Ask every time” can’t be set, and then never show the dialog in Private Browsing mode, regardless of the user’s privacy settings. OR, you could try to create some hella complex options for private browsing…

  14. leandro says:

    I’m sure you had a lot of hard work, but I want to say thank you!
    This feature is really awesome, i’ve been waiting for something like this for ages… And it open a lot of interesting ways that the addons’ developers can follow.

    Congrats and thank you again, Ehsan

  15. Ehsan Akhgari says:

    Thanks for your feedback!  I think your suggestion of never showing this dialog might have some merits.  I posted your comments on the relevant bug in Bugzilla, so we will consider it, and it may happen for the final release of Firefox 3.1 if others share my opinion as well.

  16. If am conducting a job search at work and can’t finish what I’m doing and have to revert back to my job duties (rats!) I will lose all those cool jobs I found posted on different sites. How about storing encrypted bookmarks that are automatically unlocked in private mode? That way I (and everyone else looking for a job) can be much more efficient in private mode.

    Pleeeeeeeeeeeeeeeez!

  17. [...] also released news of their new “private browsing” features. Firefox’s new feature attempts to make sure that your web browsing activities [...]

  18. Thanks and congratulation – really nice work. However, there is something in the UI that doesn’t behave the way I would expect it. Private Browsing opens a new window, you can actually see the old window being closed and the new window open up. So I would expect that closing that new window will switch off Private Browsing again. Instead, the browser exits and my old session isn’t even restored when I start it again.

  19. JinHu says:

    I would rather prefer a mix between the private mode, but in each tab like cookiepie.

    Thanks!

  20. Paul says:

    If you use Indeed.com to search for jobs, you can save any jobs in your my.indeed account. So, you can stay in Private Browsing mode and come back to Indeed.com at any time to find your saved jobs. No need for encrypted bookmarks!

  21. Ehsan Akhgari says:

    Such a feature, like this one, needs major architectural changes.  This may happen in a future release, but there simply isn’t enough time to include this in Firefox 3.1.

  22. Ehsan Akhgari says:

    Thanks a lot for your feedback.  Actually, the original UI plan was to restore the non-private session as soon as the last window in Private Browsing mode is closed.  But we thought that it would be awkward, because then the close button would have two different semantics based on the state of the browser.  But your suggestion of restoring the old session if exiting inside the Private Browsing mode is certainly worth considering, so I mentioned it here.  This may also be included in the final release of Firefox 3.1, hopefully.

  23. Ehsan Akhgari says:

    This doesn’t fall into the scope of Firefox per se, but it would be an area where an extension can help…

  24. Visitor says:

    If you’re going to show text indicating what is and what is not stored, be sure to mention that Flash cookies will continue to be stored.

  25. [...] 3.1 intègrera un mode privé permettant de surfer sans laisser de traces sur son ordinateur ce qui ne veut pas dire que vous [...]

  26. [...] 3.1 intègrera un mode privé permettant de surfer sans laisser de traces sur son ordinateur ce qui ne veut pas dire que vous [...]

  27. Pete Austin says:

    Any chance of making this property link-specific?

    I’d prefer the situation where clicking a desktop link that was saved from private mode launches Firefox in private mode, and clicking other links doesn’t.

    That way I could automatically use private mode for most Web use, but get the benefit of browser history with sites that I visit while doing research, such as Techmeme.

  28. [...] So are you excited to see private surfing added to Firefox or is this one of those “ehh, I guess it is ok” features for you too? Learn more about it at ehsanakhgari.org.  [...]

  29. [...] 3.1 intègrera un mode privé permettant de surfer sans laisser de traces sur son ordinateur ce qui ne veut pas dire que vous [...]

  30. [...] if you’re feeling adventurous, you can try the latest Firefox 3.1 build which finally has this feature. It’s simple – although not as elegant as in Chrome, which [...]

  31. [...] if you’re feeling adventurous, you can try the latest Firefox 3.1 build which finally has this feature. It’s simple – although not as elegant as in Chrome, which [...]

  32. [...] Read the Entire Story…Source: Ehsanakhgari [...]

  33. [...] Akhgari has more information available about private browsing, and thankfully he’s put forth a possible application that doesn’t directly involve [...]

  34. [...] seinem Blog beschreibt der Firefox-Entwickler Ehsan Akhgari das zukünftige Feature, welches inzwischen spöttisch als [...]

  35. [...] seinem Blog beschreibt der Firefox-Entwickler Ehsan Akhgari das zukünftige Feature, welches inzwischen spöttisch als [...]

  36. Ehsan Akhgari says:

    Not all users have Flash installed.  Others might have it installed but disabled it.  And the same goes for any other plugin besides Flash which might store data about your browsing history…

  37. Ehsan Akhgari says:

    I agree that this would be a useful feature to support, but as I mentioned in response to previous comments, this would require major architecture changes in the Mozilla code base, which may or may not happen in a future release.

    • [...] There are several new features, but the one that most users will be using is the new private browsing available. Basically, this is mode that will allow you to serf the web as normal, but when you are done, you can erase ALL evidence of your activities.  The example situation given would be searching for a new job while at your current empoyer. Check out more about private browsing. [...]

  38. Estetik says:

    of the cool new features of the upcoming Firefox 3.1 is Private Browsing. Essentially, when you enable Private Browsing, nothing of what you do in Firefox is recorded

  39. [...] Don’t leave a trace: Private Browsing in Firefox | Ehsan Akhgari 4 Nov 2008. For example, it records a history of all the web pages you have visited. To start, just select Private Browsing from the Tools menu… Mozilla Firefox 3 .1 Beta 2 Released « semuada.com – 2010-05-14 07:19 Don’t leave a trace: Private Browsing in Firefox | Ehsan Akhgari [...]

  40. [...] Don’t leave a trace: Private Browsing in Firefox | Ehsan AkhgariAnd you’ll immediately see a private browsing window, which will leave no traces of your browsing history. Useful! … The other thing that private browsing is useful for is checking your email on somebody else’s computer – no danger of cookies lying around letting them back into your email account once you’ve gone. [...]

  41. Mana says:

    ;) good to see your work’s done!

  42. Ehsan Akhgari says:

    Thanks for your support!   I hope this would be a useful addition to Firefox.

  43. [...] to the pre-release (developer) versions of Firefox 3.1, according to a blog post by Ehsan Akhgari: Don’t leave a trace: Private Browsing in Firefox. He also explains how to start Firefox in Private Browsing mode. However, as he says: Private [...]

  44. [...] добавлен новый режим Private Browsing; [...]

  45. [...] you may want to use such a feature. The developer who designed private browsing for Firefox has shared some details about how it works and how to use [...]

  46. [...] has also posted the about:config setting needed to set Private Browsing as your default browsing configuration. Once you’re in the [...]

  47. [...] has also posted the about:config setting needed to set Private Browsing as your default browsing configuration. Once you’re in the [...]

  48. [...] you may want to use such a feature. The developer who designed private browsing for Firefox has shared some details about how it works and how to use [...]

  49. [...] has also posted the about:config setting needed to set Private Browsing as your default browsing configuration. Once you’re in the [...]

  50. [...] new Private Browsing Mode that allows users to browse without Firefox storing any traces of where they’ve [...]

  51. [...] new Private Browsing Mode that allows users to browse without Firefox storing any traces of where they’ve [...]

  52. [...] has also posted the about:config setting needed to set Private Browsing as your default browsing configuration. Once you’re in the [...]

  53. [...] неща много, но за мен най-значими са възможностите за браузване инкогнито (без да оставяте каквито и да е следи – бисквитки или [...]

  54. [...] Da er betarunde nummer to i gang for Firefox 3.1. Den nye betaversjonen inneholder blant annet en ny javascript-motor, som skal gjøre nettbaserte applikasjoner raskere, og en ny funksjon for privat nettlesing. Privat nettlesing innebærer at Firefox ikke lagrer noe informasjon om nettstedene du har vært på. Les mer om privat nettlesing. [...]

  55. Handy for hiding what you’ve been looking at on ebay, or what online retailers you’ve been checking out. Great for Christmas shopping for the family, or for planning a surprise vacation.

  56. [...] has also posted the about:config setting needed to set Private Browsing as your default browsing configuration. Once you’re in the [...]

  57. [...] you may want to use such a feature. The developer who designed private browsing for Firefox has shared some details about how it works and how to use [...]

  58. [...] posible que quieras usar dicha característica. El desarrollador que diseñó la característica ha creado un artículo acerca de [...]

  59. [...] novo Modo de Navegação Privativa que permite a você navegar sem que o Firefox guarde qualquer vertígio dos sites que visitou – [...]

  60. [...] less savory reasons you may want to use such a feature. The developer who designed the feature has authored some details about how it works and how to use [...]

  61. [...] less savory reasons you may want to use such a feature. The developer who designed the feature has authored some details about how it works and how to use [...]

  62. Visitor says:

    I have my browser configured to clear private data (all boxes) after each session.
    How does this feature differ from that. ?

  63. [...] in über 50 Sprachen (Download Deutsch 16,6 MB). Hinzugekommen ist unter anderem ein neuer “Private Browsing Mode“, der über die Tools aktiviert wird. Hier entlang zu den gesamten [...]

  64. [...] laut PR-Meldung (Arcendo Communications) folgende Neuigkeiten zu bieten hat: blockquote> – Der neue Privat-Browsing-Modus hinterlässt keine Hinweise über die besuchten Seiten auf dem Rechner – Mit neuen [...]

  65. [...] the announcement that Firefox 3.1 Beta 2 will incorporate what they are calling private browsing I sigh with an air of resignation and start thinking about funny / legitimate reasons to use this [...]

  66. [...] new Private Browsing Mode that allows you to browse without Firefox storing any traces of where you’ve been – perfect for [...]

  67. [...] This was missing in Firefox though it was in other browser like Chrome,IE and Safari. Details [...]

  68. Ehsan Akhgari says:

    With that setting, private data will still be recorded to disk while browsing, but with the Private Browsing mode, those data never touch the disk, so you will be safe even if Firefox crashes, power gets disrupted, etc.

    Also, and more importantly, Private Browsing doesn’t touch the existing data (such as history), the data recorded outside of private browsing mode will be retained.  You should note that such data could be useful, for example history data can be used by Firefox to guess the place you want to visit in the smart location bar.  So, you don’t really want to discard all those data just to make sure a certain browsing session remains private.

    Setting the browser to clear all private data at the end of each session is somehow like setting the autostart preference for Private Browsing to true as I explained in the post, but considering the first point in my comment, you should prefer to use the autostart option instead of that.

  69. [...] new Private Browsing Mode that allows you to browse without Firefox storing any traces of where you’ve been – perfect for [...]

  70. [...] new Private Browsing Mode that allows you to browse without Firefox storing any traces of where you’ve been – perfect for [...]

  71. [...] new Private Browsing Mode that allows you to browse without Firefox storing any traces of where you’ve been – perfect for [...]

  72. [...] new Private Browsing Mode that allows you to browse without Firefox storing any traces of where you’ve been – perfect for [...]

  73. [...] less savory reasons you may want to use such a feature. The developer who designed the feature has authored some details about how it works and how to use [...]

  74. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  75. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  76. Ehsan Akhgari says:

    Open about:config, and type browser.privatebrowsing.autostart in the Filter text box, and double click this preference to set its value to true.

  77. Ehsan Akhgari says:

    Currently, the Mozilla technology does not allow the private browsing mode to be a per window setting, instead of a global setting, but this will probably change in the future versions of Firefox.

    As for the term to use instead of "Private Browsing", I’d rather leave that to marketing , though I suspect that the decision is to go with this exact term in the final release of Firefox 3.1.

  78. Visitor says:

    Would it not be better to simply provide for separate storage areas for profiles, and have a feature that allows one to
    a) encrypt these on the fly
    b) allow one to limit the storage of these (to 0 if necessary)

    That way one could have a a ‘private’ profile session alongside one’s regular one, so that it is not necessary to close the non-private session. In addition, due to the encryption, the private session can be saved and later be reused. If one really needs total privacy (no data ever written to disk), limit the storage size to 0 or such.

  79. Ehsan Akhgari says:

    The problem with this approach is that any customizations in the user’s default profile would be lost, such as installed extensions and themes, browsing history, bookmarks, etc.

  80. Visitor says:

    thak you

  81. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  82. Visitor says:

    Hi, how can I make privacy mode a default setting.

  83. someone says:

    The Incognito private browsing mode in Google Chrome allows you to have 2 windows running together, private and non-private. However, this feature in Firefox seems to be only one or the other, which means that certain non-private websites with videos, for example, will be reloaded and hence time-consuming, upon returning from private browsing.

    Can we imitate the behaviour of Chrome, in that you do not have to disrupt what you are doing just because you went into private browsing?

    And it might be a good idea to think of a single funky term for “private browsing”.

  84. [...] „Private browsing mode“ (privataus naršymo režimas, kaip ir Microsoft Internet Explorer 8) leis jums naudotis naršykle nepaliekant jokių pėdsakų. [...]

  85. [...] your browser, no cookies, no traces at all. You can find out more details about this feature from this [...]

  86. Now that I know how to “autostart” private browsing its not so critical, but in my windows 3.1beta2 copy private browsing only lasts for the current session and needs to be turned on again the next time I use FireFox. This is at variance with your description above (Nov.4,2008) about check-on and check-off. Is this intentional? I’d rather have it “on” when set until I turn it back off. That’s my vote. Anyhow, thanx for a big improvement.

  87. [...] your browser, no cookies, no traces at all. You can find out more details about this feature from this [...]

  88. [...] of your Web history stored locally. The developer who designed private browsing for Firefox has shared some details about how it works and how to use [...]

  89. [...] ve geliştiriciler için deneme sürümü sağlamak amacıyla yayınlandı. Yeni sürümde “gizli gezinme modu“, web geçmişinin istediğiniz belirli bir bölümünü silmek için iyileştirilmiş yeni [...]

  90. [...] Availability in 54 local language versions. * A new Private Browsing Mode. * New support for web worker threads. * The new TraceMonkey JavaScript engine is now on by [...]

  91. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  92. bad boy on block says:

    if firefox could add to their new web browser more features like new tab homepage to display your homepage when you click on new tab that will be just great !!! and other cool features like snapback in safari 3.2

  93. [...] Added a new Private Browsing Mode. [...]

  94. [...] you may want to use such a feature. The developer who designed private browsing for Firefox has shared some details about how it works and how to use [...]

  95. [...] mais informações sobre a navegação privada no Firefox, siga aqui. Para o download em português do Mozilla Firefox 3.1 Beta 2, vá por aqui. Para mais informações [...]

  96. [...] new Private Browsing mode (a la Google [...]

  97. [...] Private Browsing: Don’t leave a trace: Private Browsing in Firefox [...]

  98. [...] Added a new Private Browsing Mode. [...]

  99. [...] Added a new Private Browsing Mode. [...]

  100. [...] Modo de navegación privado que te permite navegar sin dejar rastro en el historial (al cuál se le ha denominado modo porno). El cual puede ser activado desde el menú de Herramientas. [...]

  101. [...] information available at Mozilla developer center and Ehsan Akhgari’s blog (Ehsan is the person who was working on this feature) Share this post on [...]

  102. [...] new Private Browsing Mode that allows you to browse without Firefox storing any traces of where you’ve been – perfect [...]

  103. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  104. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  105. Visitor says:

    I’m using FF 3.6.3 and wish there were only the internal one where Start changes to Stop Private Browsing in the Tools menu.

  106. Ehsan Akhgari says:

    You should also get a "(Private Browsing)" in your title bar.

  107. Visitor says:

    I’m sorry, I guess my wording did not make it clear. “No PB external signs” meaning to say I don’t want it. I wish there were a way to remove it from the Title bar.

  108. Ehsan Akhgari says:

    Unforunately, there’s currently no way to do that.

  109. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  110. Henning says:

    Thanks for your answer. Is there already in september any way to remove it from the Title bar?

  111. No there is already in october no way to remove it. Thanks a lot for your question!

  112. Visitor says:

    3.1b2 – when i switch to Private Browsing, the sites that open (allowed when I’m not private browsing) pop-up windows via a javascript link open a totally blank (about:blank) pop-up window instead of the content they are supposed to load.
    And, since the actual url is not present in the link, there’s no way i can open the intended window by pasting the url because i don’t know the url……

  113. Ehsan Akhgari says:

    Can you please specify on which web site you see this behavior?  I tested this on this page for example, and it’s working.

  114. Visitor says:

    Hi I was wondering if there is anyway I can access/ recall the private browsing history without having to purchase special sofware? Cheers All

  115. Ehsan Akhgari says:

    No, the browsing history inside the private browsing mode is not recorded, and there is no way to retrieve that information later.  This is the main point behind the private browsing mode feature.

  116. Web Directory says:

    How can i do this? i cant see it in the tool tabs? Am i having a virus in my browser?

  117. Ehsan Akhgari says:

    Make sure that you’re using either Firefox 3.5 or 3.5.  You can see the version number in the About window accessible from the Help menu.

  118. Laptop tamiri says:

    I have FF version 3.0 installed without this feature. All i can say, i just don’t need it, because I can erase all the private date anytime I want with "clear private data".

  119. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  120. Sven says:

    Thanks for your answer.

  121. KK says:

    Hello,

    I used the private search and found no difficulties until recently. Now the history is shown when a site is repeated and when trying to clear it, only the public history search shows up for clearing and the private history remains untouchable. How to gain privated search history to then delete?

    KK

  122. Visitor says:

    Sorry –
    found out the behavior caused by the TabMixPlus extension (0.3.7.4pre.081203) – if I disable that extension, the problem disappears.

  123. Ehsan Akhgari says:

    Great to hear that your problem has been fixed.

  124. Visitor says:

    Could you confirm the method of getting private browsing to be permanent via an about:config pref please? I’d like to test how it performs with Firefox installed on a usb thumbdrive with the profile also on the thumbdrive, to see if it reduces the number of writes from doing this without private browsing on.

  125. Ehsan Akhgari says:

    You need to set the browser.privatebrowsing.autostart pref to true.  This can now be done in about:config, but we will probably enable setting this option using the application preferences dialog.

    After you set this pref, close Firefox.  When you open it again, it will work in the private mode all the time.

     

  126. DieselPoweredPC says:

    It may be promitive, Gana, but it is a step in the right direction. About somone else’s comment above, I dont think its fair to comapare Gooqle Crhome to Firefox as it is a near certainty that Gooqle has nearly unlimited resources (financially) to put out a product built from the ground up. Personally, I won’t use Chrome because I don’t agree entirely with Gooqle’s reasons for Crhome, although I can appreciate their concepts.

    Firefox will be my browser of choice on all the platforms I use. I’d run it on my Windoze Mobile if I could….

  127. EveKnight75 says:

    Who says you can’t run it on Windows Mobile?

    Mozilla Firefox, Portable Edition

    It’s designed for mobile devices and portable drives (such as USB thumb drives) which run Windows 2000/XP/Vista. There’s another version for Mac here.

    My only gripes with it are that it needs Wine to run under Linux and there are no nightly builds available.

    I usually keep the portable version of the latest stable release around while running the latest nightly build. The two don’t interfere with each other so it’s a good safety option and users who don’t like testing nightly builds can use the portable version.

    That’s why I know for a fact that the portable runs great on notebooks and desktops. Unfortunately, I can’t verify how well it works on a portable device with less room (notebooks are portable!). However, I’m sure there are plenty of other people who can verify this. Just check for reviews with a search engine.

  128. Michael Ventnor says:

    Thanks for continuing work on this feature and well done on finishing it! It looks like it took a lot of effort to implement it the way you did (as well as all the automated tests!). This is going to be a major thing that people will talk about in 3.1, so once again thanks :)

  129. Ehsan Akhgari says:

    Thank you for starting the work on this feature in the first place!  It indeed took a lot of time and energy, but I feel it was well worth it, and I’m happy that I’m responsible for a feature of this size.

  130. My big question about the private browsing function is how it interacts with Add-ons? Are they told it’s a private session and to not store anything? Or are the simply not supported in a private session?

  131. Ehsan Akhgari says:

    We do not handle add-ons from inside Firefox, but we provide a very easy to use API for extension developers to use in order to make their extensions compatible with Private Browsing.  I’m going to blog about the API that we provide for extension developers tomorrow, so stay tuned!

  132. morrijr says:

    What happens when FF is closed/crashes without the user disabling private browsing? Does FF restart with the tabs as before private browsing was enabled?

    J.

  133. Ehsan Akhgari says:

    Firefox will restore the windows and tabs as they were exactly before entering the Private Browsing mode.

  134. As you see, not much is different in the Firefox window inside the Private Browsing mode. That is intentional: after all, if you’re doing something online that you don’t want your coworkers to know about, you don’t want to raise their attention with a big sign saying PRIVATE as they pass by and glance over your shoulder.

    I think we should make the browser visually different, such as with gray location bar, in order to let the user know we are private. For private mode without any GUI notification, I would like to get it tunable using a preference, which may be accessible from about:privatebrowsing page.

  135. Ehsan Akhgari says:

    The UI team, notably Alex Faaborg, decided that visual notifications are necessary, and the latest idea as far as I know was to make the interface a bit darker.  But there is not enough time to work on this for the Firefox 3.1 release, so it’s going to be defered to Firefox Next.  In the mean time, this is a good area for extension developers.  I’m currently thinking about writing such an extension but it won’t happen until after the work on Private Browsing decreases.

  136. Visitor says:

    The problem is that this won’t work unless flash usage is also private. Currently ~/.macromedia records where you have visited. Is there a plan to handle this as well. If not, it’s little bit of a waste of time.

  137. Ehsan Akhgari says:

    There are plans to allow plugins to be notified of the private browsing mode changes.  This will probably be done in the next version of Firefox, and it will allow all plugins (not only Flash) to be aware of and support the private browsing mode.

  138. H says:

    If I understand your description correctly, why must the current session be closed? Why not just open the new private window when required and close when complete? If I have 40 tabs open within non-private window, I don’t want to wait for all of them to fire up once again post-private browsing. Suggest you implement like Google Chrome (Incognito) has done it. Thanks.

  139. Ehsan Akhgari says:

    Currently, we can’t switch the private mode per window, which means that we can’t provide a new private window like Chrome does, for example.  This requires major architectural changes to Mozilla code, and may happen in a future release.  The reason we close the current session is that without doing so, it would be difficult to determine which pages have been opened in private browsing mode, and which ones have not, and also we wouldn’t know what to do with tabs and windows opened in private mode and left open after leaving this mode.  But I’m sure extension developers come up with great ideas for this task, and will enable keeping the existing session open.

  140. Albert says:

    Nice to see this feature finally in. Looking at the bugspam, it has been a hell of a job getting it right!

  141. Ehsan Akhgari says:

    Yes, it indeed was!  Took me about 10 months to complete.

  142. [...] general availability of Firefox 3.1 beta 2 for testing. Aside from increased localization support, a new Private Browsing mode, new tab switching and preview behaviors, and support for a number of new web technologies [...]

  143. [...] Watch TV On Your Computer | MakeUseOf.com January 1, 2009Free Online Flash Cards December 31, 2008Don't leave a trace: Private Browsing in Firefox | Ehsan Akhgari December 31, 2008How to Embed MP3 Audio Files In Web Pages With Google or Yahoo! Flash Player [...]

  144. Kurt says:

    You might want to put that in the actual post. A lot of people will probably want that option set to true.

  145. Ehsan Akhgari says:

    I did that.  Thanks for the suggestion!

  146. Notyear says:

    Well, what you decided to do it’s probably the worst choice. Why can’t you just discard everything, including what’s related to the preexisting tabs and windows?

    I start private browsing => Nothing is recorded in no tab.

    Closing all the tabs is incredibly annoying.

  147. H says:

    Thanks for the feedback. I guess I will rely on Google Chrome to accomplish (it is tweaked to open in Incognito mode) until such time as extension developers have overcome the apparent architectural shortcomings.

  148. Ehsan Akhgari says:

    We may also consider changing this behavior in future releases.  Because of the amound of change that this would involve, it wasn’t considered at this stage.

  149. Ehsan Akhgari says:

    I tried to address some of the issues which lead to this decision here.  Like I said, this is an area which I expect extension developers to cover…

  150. Jason says:

    If you have Firefox 3.6, you can try out this extension that adds per-window private browsing: https://addons.mozilla.org/en-US/firefox/addon/59736

  151. [...] di progetto – si riferiscono per gran parte alla gestione dei tab, ma toccano anche la navigazione privata, vale a dire una delle novità di maggiore rilievo della seconda beta.Beltzner ha poi [...]

  152. [...] new privacy feature is included in a pre-release version of Firefox 3.1. It’s called “Private [...]

  153. [...] Private Browsing Hi, neues Feature: Tools -> Private Browsing bzw. http://ehsanakhgari.org/blog/2008-11…owsing-firefox bye, Sascha — "Oh Gott im Himmel, der du geschaffen hast die Berge, das Meer, das [...]

  154. Michael says:

    I love this new feature….. It saves me a lot of time cleaning up things…
    One added feature would be when you leave the private mode, that it would list all files that were download (ex. PDF or image files) and not automatically removed (cleaned up)… I.e. if I download a file, that it would give me a log or a list so that I can clean those up as well…

  155. Ehsan Akhgari says:

    The Download Manager, accessible from Tools | Downloads already does that.  And there is a handy Clear List button if you want to delete the whole list in one go.  Or you can select individual entries and click Delete.

  156. Mike says:

    The implementaion of this feature in Google Chrome is better, I mean why close the current non-private session? Just open a new windows with in private-mode, better no?

    Or at least give an option, something like this:

    1. End and Save the current session and start new private session.
    2. Open new windows in private-mode.
    3. Cancel.

    The wording can be better, but just to clear my point.

    Thank you guys for the good job on FF3.1!

    Mike

  157. Ehsan Akhgari says:

    Thanks for your feedback.  We also don’t think that the current implementation is ideal, but what you describe requires major architectural changes which were simply not possible for the 3.1 release.  Hopefully we would have a better implementation for a future release of Firefox.

  158. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  159. MARY says:

    I like how chrome allows you to make an incognito mode window. That way you can have a window open for "private browsing" and the other for normal browsing. I also like how they make the browser window look different when you are in incognito mode. Cool that Firefox is getting this feature. I haven’t ever used it in any of the browsers that I use, but I might someday. My web sites. burun estetiği thank you.

  160. [...] Don’t leave any tracks with private browsing mode [...]

  161. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  162. ARSPR says:

    I know that you have already answered that private mode Chrome-like (not closing non-private window) will require in-depth code changes…

    So here you have another and more difficult one (I think).

    If possible I would have 3 selectable private modes. The user would be able to select how he wants FF to work:

    1st. Like FF 3.1. So FF swaps from private to normal.
    2nd. Like Chrome. So FF opens a new private window, while original FF is kept normal.
    3rd and more difficult. Private tabs mixed with normal tabs within the same window. When you select Private, a new private tab (marked somehow) would appear. From this tab you will browse in private mode. Any new tab opened from this page through Middle Click or whatever will stay in private mode. In this way you’d have a mixture of private and normal tabs in the same window. Also if possible, through Tools or Right click menu you should be able to change the Private/Normal state of any tab. When a tab is “privatized” it stops saving critical info.

  163. Ehsan Akhgari says:

    A challenge here (besides the required code changes) is how to deliver the information about the state of a tab to the user without being too subtle (and unnoticeable) and too obtrusive.  Do you have any suggestions?

  164. [...] en la edición 3.1 Beta 2, publicada hace unas semanas, el modo de navegación privada no es una herramienta para mantener el anonimato ante los propietarios de las páginas web que visitas o tu proveedor de acceso, sólo garantiza que [...]

  165. ARSPR says:

    I can think about a few options although it need to tested in real life:

    + Using a grey background (or other selectable colour) and/or special text format (as example blue font) in the Address bar.

    + With an extra icon (example your “(PB)” placeholder icon) in the address bar, next to the bookmark star, or at the beginning of the Address bar (before the web icon).

    + Outlining the tab with a dotted pattern (of selectable colour).

    + Changing the tab text font (grey colour, italics, underlined, just another font).

    + With your “(Private Browsing)” text in the window title.

    + Any other text (as example just “PB-”) before the web name shown in the tab.

    + A text/icon in the status bar.

    + …

    But any of these markers, or any other possible ones, should be fully customizable. Maybe some people don’t want to show any sign of being in PB mode, (using it at work, not wanting to get attention because someone says “Hey! this guy is in PB mode, let’s see what he’s looking at”, …), while other users will use it just as an added security/privacy option while shopping on-line from their homes, so they will want to ABSOLUTELY know and notice which tabs/windows are on PB mode and which ones aren’t.

    In addition to the tools menu switch, I would add another one on right-click menu. If the user decides to hide any external sign of being using PB browsing, these switches would be the only available signs, and because of their position, they would be normally hidden.

  166. Ehsan Akhgari says:

    Among the solutions you suggested, those which deal with the window title, and the status bar won’t be good ideas because these parts of the application are usually associated with the application, not the tabs.  The solutions dealing with the address bar have a similar problem: the address bar is associated with the current page, not with other tabs (and users need to know whether a tab is in the private mode or not without having to actually switch to it).  The best solutions I think are the ones dealing with the tabs themselves, but even they are not perfect: what if I’m working on a specific page, but its tab is not currently displayed?  Or what if I hide tabs for single tabs in a window?  What if I have an extension installed which changes the display of tabs (such as giving it a particular color, etc)?

    Overall I think doing this will tend to confuse a lot of people, unless we have a clear way to distinguish private and non-private tabs.  Note that the implementations such as Chrome’s do this effectively by grouping tabs inside a window, which the user is already familiar with (i.e., if a tab is in Window A, then it’s private, if it is in Window B, then it’s not private).

    I’d be happy to hear from you further on this issue.  Thanks for taking the time to think about this!

  167. ARSPR says:

    Well, I think showing if you are in PB or not is not HUGELY critical as a general information. An unaware user, using PB without knowing it, will just lose History and Cookies…

    Maybe an extra PB icon in the tab could be enough as the general basis in order to distinguish between PB and normal tabs for the 3rd PB mode. And also you could put an optional switch which would kept grouped PB tabs and normal tabs. In this way you could have private tabs at the beginning and normal tabs after them. If you open a new private tab, instead of going to the right most end, it would go to the right end of the PB group.

    The other notifying options, (which are window related so they are only displayed for the current tab), just help the user about noticing if he is or not in PB (within that window/tab/session or whatever).

    But as I already said, I think these marks should be fully customizable (whichever are implemented). Some users will want FF to SHOUT, (yes, in capital letters), at them that they are in PB mode, while others won’t want any external sign of being in this mode.

    (And speaking about obvious signs of being in PB: if possible you could also code a “Private Browsing” watermark overlaid in the main window content, like “Confidential” in spy film archives ;) )

  168. [...] en la edición 3.1 Beta 2, publicada hace unas semanas, el modo de navegación privada no es una herramienta para mantener el anonimato ante los propietarios de las páginas web que visitas o tu proveedor de acceso, sólo garantiza que [...]

  169. [...] en la edición 3.1 Beta 2, publicada hace unas semanas, el modo de navegación privada no es una herramienta para mantener el anonimato ante los propietarios de las páginas web que visitas o tu proveedor de acceso, sólo garantiza que [...]

  170. [...] en la edición 3.1 Beta 2, publicada hace unas semanas, el modo de navegación privada no es una herramienta para mantener el anonimato ante los propietarios de las páginas web que visitas o tu proveedor de acceso, sólo garantiza que [...]

  171. Ehsan Akhgari says:

    Firstly, being able to determine whether or not a tab is in private mode is very important, not because that you may think that a private tab is not private, but because the reverse could happen, i.e., you may think a tab is in private mode while it’s not.

    Also, I think that extension authors may be able to provide different kinds of UI for indicating the private browsing mode status (like for example a shouting UI! ), and I’m sure some extensions which do exactly this will pop up sooner or later.

    But I think maybe we need to wait for the core code to support private browsing mode per tab instead of globally, and then we can come up with UI ideas. 

  172. Melvin says:

    Hi. I’ll throw a question most of you will find a bit stupid. I’m not a techie so I’ll just go ahead and shoot the question: Does going PB prevent the IT department from knowing which sites are you visiting?

  173. Ehsan Akhgari says:

    Yes, they can monitor your Internet activity if they choose to.

  174. Abbadabba says:

    Basically, it’s not truth. US government can somehow try t monitor us ISPs, but if you use satellite connection registered anonymously, they can’t track you

  175. Adam says:

    While PB does help, what you want is to use a proxy server while browsing the web.

    Two options:

    1. Type the proxy server IP and port into your web browser. (google free proxy servers for free public proxy IPs).

    2. Use a proxy server client such as annonymizer.com

    This method will allow you to surf all you like whilst using your work computer without the IT team knowing.

  176. WzeroJT says:

    You can also use chain proxy for more anonymity.

  177. [...] приватного web-серфинга, когда никакая информация не оседает в кеше браузера, [...]

  178. Inquiistive says:

    My version of Mozilla is 3.0.8. I do not see the option of enabling private browsing under tools menu. Is it possible that teh administrator would have removed the tool while installation?

  179. Ehsan Akhgari says:

    Private Browsing is a feature which will be part of Firefox 3.5, which will be released soon.  To test the feature right now, you need to install a Beta version of Firefox.

  180. [...] menu. There is a hidden way to make Firefox 3.1 Beta 2 always start in Private Browsing Mode and a plan to possibly provide an easier way to do this in the final 3.5 release, but the only obvious use for [...]

  181. Ehsan Akhgari says:

    Thanks for your feedback!  We have added hotkeys for entering and leaving the private browsing mode, which will be available in Firefox 3.1 Beta 3 (or currently in Shiretoko nightlies).  And you would be pleased to know that we have used the same Ctrl+Shift+P combination that you have suggested! 

  182. WGZ says:

    Nice work. Now all we need is a hotkey, like ctrl+shift+p or anything, and this is perfect. I dont believe that features used more than very seldom should be without hotkeys.

    -WGZ

  183. matt says:

    I have “prompt me” as my action for cookies. In private browsing mode this is incredibly annoying as I get a dialogue for every single cookie and I can’t tell it to permanently ignore the site.

  184. Seth says:

    I’m loving firefox! Hey Eshan what do you think of google’s chrome and their incognito option? I was just wondering what you think I am sure you guys have tried it out? Let me know.
    Seth
    Owner of Vegas Blog

  185. iNetZeal SEO says:

    LOL, I used to DELETE history in order to let other’s dont know about my activity. I am using firefox since couple of year and upgrade each time when i find new upgrade but i didnt notice this feature (thanks for heads up!). However, as you mentioned, this features is only when PCs are shared with others. In my case, my PC is my very personal PC. So, i wouldnt need to use this feature anyway!

    After upgrading to FF3, I Noticed one problem, It crashes many times in a day. Older versions had no such issues. Anyone experienced this?

  186. Ehsan Akhgari says:

    This problem was filed as bug 468700 in Bugzilla, and has been fixed on "trunk" (which will be Firefox 3.2 Alpha 1), and is currently waiting to get approval to be fixed in Firefox 3.1 Beta 3.

  187. Ehsan Akhgari says:

    Google Chrome seems like a nice browser.  I have used their incognito feature only to compare it to our Private Browsing implementation, and I have not used the browser otherwise extensively.

  188. Ehsan Akhgari says:

    If you used to delete your history to prevent others from knowing your activities, chances are that you will find the private browsing mode very useful.  Any site you visit in this mode will not leave any trace on your computer, so you wouldn’t have to delete your entire history in order to not let the others know about your activities.

    About the crash you’re mentioning, it is very likely that it’s being caused by a plugin or an add-on.  I suggest you visit this page in the Mozilla Support web site, or ask your question on the forum.

  189. Visitor Kenneth Gilbert says:

    Would it be possible to include in future versions of Mozilla a system whereby frequently used phrases can be added to the cursor by touching one or two keys eg contrl + 1 would give you your email address & contrl + 2 would give you your home address? This would save a lot of time for slow typists!

    I have recently purchased ‘Error fix’ to sort out some problems with the slowness of my computer/ISP & after running it I find that Mozilla no longer stores my username/password. How can I fix this?

  190. norble says:

    yeah, the same trouble with the cookies

  191. Ehsan Akhgari says:

    About the key stroke feature, it would be best for you to file an enhancement request at Bugzilla.  About the problem you’re facing with the usernames and passwords, I suggest you ask your question on the support forum.

  192. Chester says:

    That’s a “portable” version of Firefox, not a Windows Mobile version. There’s a big difference.

    Windows Mobile is an OS that runs on mobile phones. The portable app is a version that’s configured to run off of a portable drive, but you still need to be using it on a system running Windows 2000/XP/Vista as you pointed out. Windows Mobile is not one of those supported operating systems.

  193. Basey says:

    The Firefox private browsing feature is great, but sometimes I have to use computers where Firefox is not installed. Here is an alternative, download and run ccleaner ( search “ccleaner”).

    It’s a great little utility. Ummh, one thing though, while installing it will helpfully suggest an additional toolbar, but you can politely decline. So watch for it during installation.

  194. [...] a los desarrolladores construir aplicaciones similares a GPS. Otra muy interesante implementada es ‘Private Browsing’, que básicamente te permite navegar sin dejar huellas en donde [...]

  195. Visitor says:

    To bad it looks like you can’t just open private browsing tabs. For instance you type in the URL in the address bar and click a button that says private before pressing enter, or you if your opening up a link you can right click on the link and open as private, then a box comes up and asks if you want to always open this site up as private and you can press yes or no. This way you can have your private sites and regular sites in one browser.

  196. [...] new privacy feature is included in a pre-release version of Firefox 3.1. It’s called “Private [...]

  197. [...] More about Firefox 3.1: Private browsing in Firefox [...]

  198. [...] what exactly is Private Browsing? Ehsan Akhgari has the answer to it. Private Browsing aims to help you make sure that your web browsing activities [...]

  199. Navin says:

    I really liked the idea.

  200. Jeferson says:

    Just change the name. How about “Self Cleaning Session”? :)

  201. When you wrote “co-workers” did you really mean “wife”? But seriously, this feature has lots of uses beyond work in places such as libraries or Internet cafés.

  202. [...] trucchetto scoperto da Eshan Akhgari dopo aver approfondito tale argomento sul suo blog, spiega come fare avviare Firefox sempre in [...]

  203. venkat says:

    How many people are using private browsing to be frank I forgot about that ,what about the normal users they are not knowledgeable enough to use them it’s my personal opinion,which makes advertisers happy as these private browsing can not allow advertisements in private mode.

  204. SteveM says:

    Great feature.

    I would think that online banking would be a better example. And you’d want a visual indication: people could learn that you want the lock symbol and different colour of the location bar to indicate security, and the private browsing visual indication to indicate that none of their banking data is being accidentally cached.

    At least that’s my idea of an example. I would think that you couldn’t effectively design the feature unless you have some real ideas about what it’s meant for. “Browsing websites that you don’t want your employer to see?” come on, that’s pretty weak. Before this goes out in a release build, I think you should have a list of real-world examples of what this feature is to be used for (which will include pr0n) and make sure the use-cases are well thought out.

    This feature would be fine for me doing my online banking at home. But at work, I often have 20 work-related tabs open. I would not want to lose them all just to do my banking.

    Keep up the good work,
    Steve

  205. [...] Don’t leave a trace: Private Browsing in Firefox (Ehsanakhgari) [...]

  206. [...] development programmer Ehsan Akhgari announced, in his personal blog earlier this week, that a new ‘Private Browsing’ mode will be available in ‘pre-release’ [...]

  207. [...] new privacy feature is included in a pre-release version of Firefox 3.1. It’s called “Private [...]

  208. [...] if you’re feeling adventurous, you can try the latest Firefox 3.1 build which finally has this feature. It’s simple – although not as elegant as in Chrome, which [...]

  209. [...] browser Chrome made in Google, è un atto dovuto per allinearsi alla concorrenza. Ehsan Akhgar illustra sul suo blog l’utilità di una tale modalità, considerando ciò che viene memorizzato in [...]

  210. Ehsan Akhgari says:

    Yes, I agree that this would be very useful feature.  This may be included in a future release of Firefox.

  211. Ehsan Akhgari says:

    Well, "Private Browsing" was what the initial feature request in our bug tracking system was called, which is coming from Apple’s Safari.  As far as I know, the plans are to ship the feature in Firefox 3.1 with the same name, which tends to be a more familiar to users.

  212. Ehsan Akhgari says:

    Yes, especially with the auto-start mode turned on.  In that case, each user who sits at a computer can open the browser, do her work, and just close it.

  213. Ehsan Akhgari says:

    I’m not sure what you mean here.  I have no data on the number of users using the private mode, but Private Browsing is not about filtering online ads, and you will get the ads inside the private mode as well if you don’t have another way to filter them.

  214. Ehsan Akhgari says:

    Actually the use case you’re describing is a by-product use case, but it’s a good one anyway!  Thanks for sharing it.

  215. Blog says:

    [...] new privacy feature is included in a pre-release version of Firefox 3.1. It’s called “Private [...]

  216. [...] This post is targetted at Mozilla extension developers and theme designers.  See my previous post for a general overview of the Private Browsing [...]

  217. [...] in browsers is continuing fast and furious. Just today "private browsing" was added to an official Firefox build and that’s sure to be appealing to users mainstream and early [...]

  218. [...] 248970 – Private Browsing mode. (Ehsan’s blog posts: screenshots, information for extension developers and theme [...]

  219. [...] on its laurels, either. Version 3.1 is expected early next year, with an array of new features like private browsing, visual tab-switching, and a host of other [...]

  220. [...] of the cool new features of the upcoming Firefox 3.1 is Private Browsing. Essentially, when you enable Private Browsing, nothing of what you do in Firefox is recorded. [...]

  221. Martijn says:

    You already mention that one does not want to have PRIVATE in big letters to indicate a Private Browsing session.
    However, also showing it in the title bar and tab could already be too much.

    Google Chrome just adds a small icon near the location bar to indicate what they call an Incognito Window:
    http://www.google.com/support/chrome/bin/answer.py?answer=95464&hl=en-US
    And the title bar of the window gets a darker look. The latter could interfere with themes in Firefox.
    But I guess you could use the part that shows the favicon to indicate a private browsing session.

    Now when a website has a security certificate associated with it the favicon-area gets a blueish background color.
    In the same way you could choose another color to indicate a Private Browsing session, so that only the one who is using the browser knows that it is private.
    Of course, when this feature becomes popular also other experienced Firefox users will know about this, but you could make the indication less obvious.

  222. Ehsan Akhgari says:

    Ultimately, there are two absolute solutions here.

    • Do not provide any user interface notifications at all in private mode.
    • Provide a very visible notification in the primary user interface when inside the private browsing mode.

    I think Google Chrome’s approach is near the second solution above, as the icon it provides is easily viewable with a glance (e.g., when someone walks by and take a quick look over your shoulder).  The same goes for Internet Explorer’s InPrivate mode.  For Firefox, an idea we had was to darken the whole theme a bit in private browsing mode, and that would be near the second solution as well.

    However, for this release, we decided to just stick to the title bar change.  One can argue that this would be more near to the first solution above, because text in general is not as eye-catching as graphics, and also the title bar is traditionally ignored by many users (which may be good or bad in this context).

  223. Asher says:

    keeping a list of “private browsing sites” would be counter-productive to keeping one’s privacy. It would provide information the user is frequently visiting these sites, or at least has visited them in the past AND tried to disguise this information.
    … Unless it’s all encrypted via password manager…

  224. Ehsan Akhgari says:

    You’re right, we would need some kind of password protected encryption for such a list, if we ever decide to implement it.

  225. [...] habe keine Ahnung, was Du damit meinst. Das ist der neue Firfox Porno-Modus. Hat SM nach nicht. http://ehsanakhgari.org/blog/2008-11…owsing-firefox bye, Sascha — "Oh Gott im Himmel, der du geschaffen hast die Berge, das Meer, das [...]

  226. Tommy_B says:

    (Hey, first of all… great post… thanks for taking the time…)

    I hate making statements like that (about FF missing the boat) – especially because Firefox when I found it somewhere closely after 2.0, was like heaven sent, a real gift to work with. IE for Mac was (thankfully) being written off by M$ and I tried convincing myself from day one that Safari when it came out was an IE killer when in fact Safari just sucks, it always has (in varying degrees) and chugging along at v.4 (b) isn’t dramatically different except it’s got the killer developer tools right at your finger tips AND coverflow for bookmarks so it looks like its doomed for inevitable suck-dom.

    It’ll be a couple years before there’s really heated competition… on all levels, as a whole… but with Google Chrome’s implementation of private browsing including the “multiple instances”-esque approach and this browsa called Stainless for Mac (a Chrome knock offwhich has had 100% success in the 6 months I’ve been testing it in effectively submitting masked User Agents – I feel bad for things like Opera that still battle it out one on one with individual websites despite their feature to change User Agent) with it’s private browsing & tab specific cookies allowing multiple log ins under different credentials to the same site… I think Firefox made the best decision for the here and now but who knows how long before people smarten up and start to feel the FF implementation is a dumbed down version of PB’ing. And from reading the Mozilla PB wiki https://wiki.mozilla.org/PrivateBrowsing, it sounds like they put a lot of long hard work into it.

    And I wonder how PBing will play out in enterprise… I don’t know the distribution stats about FF in business, but the majority of Fortune 500 co’s expressly forbid browsing that is not work related and usually block a bunch of domains known to suck up your day.

    I am terribly thrilled though with the new tear away tabs! I often have my laptop hooked up to my flat screen and will browse for something to watch on it and then have to either drag the whole window which may have other tabs with it over to the TV only to drag it back when video is done or cut n paste url to new window on the TV.

    (and a big thumbs down to geolocation – you tell SOMEBODY, ANYBODY who will listen that they have done more harm then good by releasing this pathethic information http://www.mozilla.com/en-US/firefox/geolocation/ which is pretty much standard FF disclosure and business as usual for any feature. It’s pathetic because there’s absolutely no end-user justification presented AT ALL. Just “talk to a third party about what they are going to do with your information.” This isn’t like having a cell phone and being lost in the woods and tracked down for rescue by helicopter. It’s bad enough IP addresses get submited all over the place. But I’ll find another blog to cry about this on.)

  227. S M K sagar says:

    There have been many intelligent suggestions on hiding the PB mode from peepig toms while at the same time reminding the user that he is in PB mode or otherwise.

    I have a suggestion that may achieve both.
    The user can select a thumbnail image from his /her image collection THAT would be his personal cutomized reminder that the user is in private browising mode without anyone suspecting it. ONLY THE USER KNOWS WHAT THAT ICOn / IMAGE MEANS.

    This thumbnail can sit as an ICON in the address bar / side bar

    Laternatively it can be a part of the web page at a fixed location so that it appears as just one of the images to anyone with passing curiosity.

    Since I am not a software engineer, I cannot comment on the technical feasibility of this BUT it should be posssible to implement this.

    User can frequently change this image. Obviously the image sgould be some kind of gawdy or eye-candy & not very dull if it to serve this purpose proper

  228. Ehsan Akhgari says:

    Thanks for your feedback!

    I’m afraid that with your suggestion, the presence of the icon itself might be an indicator of the private browsing mode being active.  That is, if someone passes by and notices an image in an unusual location, the fact that the image is there is enough for them to tell whether the private browsing mode is active or not.

  229. Victor says:

    I hate it when people come to my house and do something and then click the click private data, they delete my information, now with the feature you described here it solves the problem. I will tell everyone who approaches my computer to wait a second will turn this feature on and will explain what it does and when they go I will disable it.

    Thanks for that info

  230. Visitor says:

    makes me wonder what you let people use your computer for Oo

  231. Ehsan Akhgari says:

    Yes, such a button is already available using the Toggle Private Browsing extension which I have written about before.

  232. Visitor says:

    Hello,

    Will there be a button that I can add to the toolbar to enable/disable this feature more quickly than going into the tools menu? I’d like to see this feature.

    Lee

  233. Visitor says:

    I realize that the data from the browsing session will not be stored in the regular memory of my computer, but will files used by the browser be found in the partition memory if someone were to go looking there?

  234. Ehsan Akhgari says:

    I’m not sure what you mean by "partition memory", but in private browsing mode, no personal information will be stored on any part of your hard disk.

  235. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  236. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  237. nemo says:

    I have FF version 3.0 installed without this feature. All i can say, i just don’t need it, because I can erase all the private date anytime I want with "clear private data".

  238. One Way Only says:

    Hello Ehsan Akhgari,

    I’ve used FF private browsing for internet banking for a long time, because I felt safer if *nothing* was written to disk on a PC dedicated to this task, though https traffic shouldn’t already be saved.

    Maybe, I misunderstood how FF PB works, but I saw a strange behavior in the latest FF versions (3.6.4 and 3.6.6).

    Here what happens to me:

    http://forums.mozillazine.org/viewtopic.php?f=38&t=1932683

    Is a normal behavior?

    I see a potential risk to privacy (and my bank account too), because I don’t know *what* is being written to disk.

  239. Ehsan Akhgari says:

    We make the promise of never writing anything to disc which can be used to identify the websites that you’ve visited inside private browsing mode.  What kind of data are you actually talking about?

  240. One Way Only says:

    I can see via Windows Task Manager that FF has large disk activity when flash and other plugins’ stuff is loaded in Private Browsing mode.

    Previously, the FF process in the task manager didn’t show such activity.

    However, I’ve read this page:

    http://www.adobe.com/devnet/flashplayer/articles/privacy_mode_fp10.1.html

    and I suppose I’ve misunderstood how the plugins worked in the private browsing of previous FF versions.

    Now, according to Adobe, at least Flash should *delete* whatever has *written* to disk, if in private browsing. A behavior taht is different from FF default, but equal to IE or other “private” mode.

    I don’t know if this is the reason why both “firefox.exe” and “plugin-container.exe” are showing disk activity in my task manager.

    My Firefox version is a clean installation of 3.6.4 upgraded to 3.6.6 without any extension.

    So far, nobody on Usenet and Mozillazine threads has confirmed this disk activity, so I don’t know if it’s normal or something strange happening on my system.

  241. Ehsan Akhgari says:

    The mere presence of disk activity is not strange.  Flash could be using the disk to store its information, and firefox.exe and plugin-container.exe might also use the disk to communicate back and forth with each other, but none of that should be counted as suspicious activity, unless you can see any files written on disk which include your browsing history information (such as the sites you’ve visited, etc.)

  242. One Way only says:

    Thanks for your answer.

  243. motoculteur says:

    would it be ok to get a private browsing in the title bar as someone mentioned up there?

  244. Ehsan Akhgari says:

    We already get "(Private Browsing)" in the title bar in Firefox 3.5 and 3.6.

  245. Ehsan Akhgari says:

    No, that probably means that you all of your downloads have been resumable.  Please note that most web downloads are resumable, so encountering an unresumable web download is an uncommon situation.

  246. Ehsan Akhgari says:

    Ah, that’s interesting.  Yes, you’re right; I guess we should prompt whether or not the download is resumable when leaving the private browsing mode.  I have filed a bug in the Mozilla bug database about this, and will work on fixing it.  Thanks for reporting this!

  247. Visitor says:

    You’re welcome,

    Just wanted to clarify a couple of things about the comment you made earlier…

    Referring to resumable downloads, you said: “If it is, we just pause it silently, and restart it when you leave the private browsing mode.”

    It occurred to me that a download which was started in “Private Browsing” is a private download, so IMHO should only be restarted when “re-entering” private mode, not when “leaving”.

    However, even if that was the case, does being able to restart it mean that some record of the partial download would have to exist in the non-private browser cache? It seems to me that this would defeat the purpose….

  248. Ehsan Akhgari says:

    I was talking about downloads started from the normal browsing session.  Downloads started from private browsing mode should either be cancelled at the end of that mode, or the user should wait for them to complete before leaving the private mode.  We can’t store records of them so that they would be restarted when entering another private browsing mode session (and it doesn’t make much sense since any private browsing session is isolated with regard to other such sessions.)

  249. Visitor says:

    Perfect.

    That’s all exactly how I thought it should work.
    (I had previously thought that you were talking about DL’s started within private mode)

    Thanks for the clarification.

  250. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  251. Visitor says:

    In your description above, you say:

    This action discards all of the data from your private session, and will restore your non-private browsing session, just like it was before entering the Private Browsing mode.

    This leads me to believe that data is at some point written to disk and then later “deleted”. Can you clarify if this is, or is not, the case. If data is written during PB and then erased at the end, then this is no different than Clear Private Data function, and is not secure since the files can be recovered. I understood PB to mean that no data was ever written to disk (unless you download or open a file using a native application).

    Please clarify.

    Thanks

  252. Ehsan Akhgari says:

    No, the data you’re talking about is never written to disk during the private browsing mode.  By "discarding" I meant that Firefox clears them from main memory.

    This way if your browser crashes during a private browisng session (or there is a power outage, or any other reason why Firefox would not be able to shut down clearly), then no traces of your browsing would remain on the hard disk of your computer.

  253. I’ve never seen such a warning.

  254. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  255. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  256. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  257. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  258. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  259. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  260. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  261. Visitor says:

    When you quit private browsing, it’s easy to forget if you have any downloads in progress. Any downloads which are in progress get canceled as well.

    It would be useful to have some sort of warning when you try to quit private browsing:
    eg.
    “You have active downloads in progress. Are you SURE you want to quit private browsing at this time?”

  262. Ehsan Akhgari says:

    We actually do show such a warning if the download is not resumable.  If it is, we just pause it silently, and restart it when you leave the private browsing mode.

  263. Visitor says:

    There may be a bug then, because I’ve never seen such a warning.

  264. Visitor says:

    Note: Something I didn’t make very clear is that I’m talking about when you “Stop Private Browsing” in the Tools menu, rather than quitting the browser altogether.

    For “resumable” downloads I assume that you meant to say “when you re-enter private browsing mode”

  265. Visitor says:

    I won’t need it or use it, and would love to know how to use about config or something to remove it from Tools menu with 3.5
    please and much thanks!

  266. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  267. Ehsan Akhgari says:

    Unfortunately, there is no way to remove this feature from the Tools menu.  But I suppose if you don’t use it, you can simply ignore it, and it won’t change any of the usual behavior of the browser.

  268. Spiridon says:

    nice post! Thanks.

  269. Ehsan Akhgari says:

    Thanks for the kind words!  I’m glad that you find this feature useful.

    As about having some sites trigger the private browsing mode, this can’t be easily done right now because the private browsing setting is global (and not per tab/window), but I guess this can be implemented if someone steps up to write an extension for it.

  270. Timo says:

    Thanks for such a great feature. I will surely use this for private browsing at work (which is allowed, but I still don’t want anyone be able to browse through my private browsing history when sitting at my computer).
    What I would additionally like to have though would be some automatic activation/deactivation of the private browsing mode based on a configurable list of web sites (that list would have to be password-protected of course). I will else surely often forget to switch on the private browsing mode, or forgot to switch it off afterwards.

  271. rana says:

    This means we cannot do private/non-private together :(
    Then this is primitive.

  272. Neil P says:

    A similar function is already employed by the IE Tab extension. You can specify (with wildcard characters) certain sites that will open in an IE tab by default. That extension could probably be used as a base to provide the same feature for Private Browsing.

  273. Ehsan Akhgari says:

    I’m not sure if that would be possible, since that extension embeds another rendering engine in a Firefox tab, but for private browsing, it has to embed a full instance of Firefox inside a tab, which may not be possible.

    I could be wrong though…

  274. [...] 3.1 beta 2 is out for testing, including “Porn Mode” & Trace Monkey (new JS engine) amongst other features. Go download! Spread the [...]

  275. [...] are un mod nou de browsing incognito numit -  Private Browsing Mode; [...]

  276. [...] caratteristica più evidenziata nelle note di rilascio è la modalità di “navigazione privata” grazie a cui è possibile non lasciare tracce dei siti visitati e rimuovere parti della [...]

  277. [...] מצב גלישה פרטית המאפשר לך לגלוש כאשר Firefox לא שומר עקבות של האתרים בהם ביקרת. [...]

  278. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  279. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  280. [...] A new Private Browsing Mode or more popularly dubbed as the Porn Mode. {more info} [...]

  281. [...] Si eres valiente, claro. Se acaba de hacer disponible la nueva versi

  282. [...] ehsanakhgari.org/blog/2008-11-04/dont-leave-trace-private-browsing-firefox here’s a way to make Firefox always start in Private Browsing mode:  Go to the [...]

  283. [...] keine Informationen dauerhaft abgelegt. Weitere Details zu dieser Funktion findet man im Blog von Esan Akhgari. Eine weitere wichtige Neuerung nennt sich “Web Worker”. Dabei handelt es sich um eine [...]

  284. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

  285. [...] preview release intended for developer testing and community feedback. New features include a private browsing mode, new functions that make it easy to remove specific portions of web history, a new javascript [...]

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  1. [...] caratteristica più evidenziata nelle note di rilascio è la modalità di “navigazione privata” grazie a cui è possibile non lasciare tracce dei siti visitati e rimuovere parti della [...]

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